KR20200111531A - Battery module and device including the same - Google Patents

Abstract

The present invention relates to a battery module with improved the welding reliability of a battery module frame by preventing a blow hole phenomenon in a welding process, and to a device including the same. According to an embodiment of the present invention, the battery module comprises: a cell stack including one or more battery cells; a battery module frame housing the cell stack and having front and rear surfaces facing each other; and an end plate covering each of the front and rear surfaces of the battery module frame, wherein the battery module frame includes a first bonding surface formed on sides constituting each of the front and rear surfaces, the end plate includes a second bonding surface bonded to the first bonding surface, and an indent part is formed in at least one of the first bonding surface and the second bonding surface to be in contact with each other.

Description

Battery module and device including the same {BATTERY MODULE AND DEVICE INCLUDING THE SAME}

The present invention relates to a battery module and a device including the same, and more specifically, to a battery module with improved weldability between metal frames and a device including the same.

As the use of portable devices such as mobile phones, notebook computers, camcorders, and digital cameras has become common in the modern society, the development of technologies in the fields related to such mobile devices is becoming more active. In addition, rechargeable rechargeable batteries are a way to solve air pollution, such as conventional gasoline vehicles that use fossil fuels, such as electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles ( P-HEV) is used as a power source, and the need for development of secondary batteries is increasing.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries, among which lithium secondary batteries have little memory effect compared to nickel-based secondary batteries, so charging and discharging are free. , The self-discharge rate is very low and the energy density is high.

These lithium secondary batteries mainly use lithium-based oxides and carbon materials as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are applied, respectively, are disposed with a separator therebetween, and an exterior material that seals and accommodates the electrode assembly together with an electrolyte solution, that is, a battery case.

In general, a lithium secondary battery may be classified into a can-type secondary battery in which an electrode assembly is embedded in a metal can and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch of an aluminum laminate sheet according to the shape of the exterior material.

In the case of secondary batteries used in small devices, 2-3 battery cells are arranged, but in the case of secondary batteries used in mid- to large-sized devices such as automobiles, a battery module electrically connecting a plurality of battery cells Is used. In such a battery module, a plurality of battery cells are connected in series or parallel to each other to form a cell stack, thereby improving capacity and output. In addition, one or more battery modules may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.

On the other hand, in order to protect the cell stack from external shock, heat or vibration, the battery module has a battery module frame and a front side of the battery module frame that has the front and rear sides open to accommodate the cell stack in an internal space. And it may include an end plate (End plate) covering the rear.

Welding may be performed for bonding between a battery module frame made of metal and an end plate, and FIG. 1 is a photograph showing a welding bonding surface between a conventional battery module frame and an end plate. However, referring to the area indicated in FIG. 1, a blow hole phenomenon in which compressed pores remaining inside the metal of the battery module frame or end plate burst out may occur during the welding process, thereby improving welding reliability. It causes the decline.

The problem to be solved by the embodiments of the present invention is to solve the above problems, and a battery module including the same and improved welding reliability of the battery module frame by preventing a blow hole phenomenon in the welding process. To provide a device.

A battery module according to an embodiment of the present invention includes a cell stack including one or more battery cells; A battery module frame housing the cell stack and having front and rear surfaces facing each other; And an end plate covering each of the front and rear surfaces of the battery module frame, wherein the battery module frame includes first bonding surfaces formed on sides constituting each of the front and rear surfaces, and the end plate comprises: And a second bonding surface bonded to the first bonding surface, and a depression is formed in at least one of the first bonding surface and the second bonding surface.

The indentations may extend along a direction parallel to sides constituting each of the front and rear surfaces of the battery module frame.

The indentation may be indented in a direction perpendicular to the first bonding surface or the second bonding surface.

The indentation may be formed to be spaced apart from sides of the first bonding surface or sides of the second bonding surface.

The indentation may have a V-shaped, square or semicircular shape.

Each of the battery module frame and the end plate may include an aluminum alloy.

The first bonding surface and the second bonding surface may be welded to each other.

The end plate may further include a protrusion positioned at a center side of the end plate than the second bonding surface and protruding toward the battery module frame.

The protrusion may extend along a direction parallel to sides of the end plate.

According to the embodiments of the present invention, since the direction in which the compressed pores inside the metal move can be adjusted by forming a depression in the bonding surface where welding is performed, it is possible to prevent a blow hole phenomenon from occurring in the bonding surface of the battery module frame. have.

1 is a photograph showing a bonding surface between a conventional battery module frame and an end plate.
2 is a perspective view showing a battery module according to an embodiment of the present invention.
3 is an exploded perspective view of the battery module of FIG. 2.
4 is a partial perspective view of an upper right part of the battery module of FIG. 2 after being cut along the cutting line A-A'.
5 is an enlarged view of a battery module according to another embodiment of the present invention.
6 and 7 are views showing variously modified indentations in an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description have been omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not necessarily limited to the illustrated bar. In the drawings, the thicknesses are enlarged to clearly express various layers and regions. And in the drawings, for convenience of description, the thickness of some layers and regions is exaggerated.

In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, this includes not only "directly over" another part, but also a case where another part is in the middle. . Conversely, when one part is "directly above" another part, it means that there is no other part in the middle. In addition, to say "on" or "on" the reference part means that it is located above or below the reference part, and means that it is located "above" or "on" in the direction opposite to gravity. no.

In addition, throughout the specification, the term "on a cross-sectional view" means when the cross-section of the target portion is cut vertically when viewed from the side.

In addition, throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

2 is a perspective view showing a battery module 100 according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the battery module 100 of FIG. 2.

2 and 3, the battery module 100 according to an embodiment of the present invention accommodates a cell stack (not shown) and a cell stack (not shown) including one or more battery cells. And an end plate 300 covering the front 201 and the rear 202 of the battery module frame 200 and the battery module frame 200 with the front 201 and the rear 202 facing each other. .

More specifically, the battery module frame 200 may be in the shape of a rectangular metal plate in which the front surface 201 and the rear surface 202 are opened, and the four sides 211 and the rear surface 202 constituting the front surface 201 Includes four sides 212 constituting ).

FIG. 4 is a perspective view of a portion of the upper right after cutting the battery module of FIG. 1 along the cutting line A-A', and in particular, an area where the front surface 201 of the battery module frame 200 and the end plate 300 are joined. Show enlarged.

Referring to FIG. 4, the battery module frame 200 includes a first bonding surface 230 formed on sides 211 constituting the front surface 201 of FIG. 3, and the end plate 300 is a first bonding surface. It includes a second bonding surface 330 bonded to (230).

The battery module frame 200 and the end plate 300 include metal, and a material constituting the metal will be described later. To bond the battery module frame 200 and the end plate 300 made of metal, the first bonding surface 230 and the second bonding surface 330 may be welded to each other.

Referring again to FIG. 4, a recess 340 may be formed in the second bonding surface 330. More specifically, the indentation portion 340 is indented in a direction perpendicular to the second bonding surface 330 and parallel to the sides 211 constituting the front surface 201 shown in FIG. 3 (X direction). It may be a shape that extends along. That is, the indentation 340 may provide a passage through which the gas moves between the first bonding surface 230 and the second bonding surface 330.

In order to manufacture the battery module frame 200 or the end plate 300, a die-casting method may be used, and in the process, compressed inside the battery module frame 200 or the end plate 300 Pore can be formed.

At this time, if the indentation portion 340 is not provided, a blow hole phenomenon in which the compressed pores as described above burst out toward the outside of the battery module during welding may occur, thereby reducing welding reliability. .

In contrast, according to the present embodiment, since the indentation portion 340 extends in a direction parallel to the sides 211 constituting the front surface 201, the compressed pores inside the metal are changed in the X direction in FIG. You can induce them to move along. As a result, it is possible to prevent a blow hole phenomenon in which compressed pores are eventually blown out of the surface where the first bonding surface 230 and the second bonding surface 330 are bonded, so that the battery module frame ( 200) and the coupling force of the welding joint between the end plate 300 is increased.

Referring again to FIG. 4, the indentation 340 is preferably formed to be spaced apart from the sides of the second bonding surface 330. Among them, it is more preferable to be spaced apart from the side of the second bonding surface 330 located on the upper side, that is, the side exposed to the outside of the battery module. Otherwise, since the indentation portion 340 is adjacent to the outside of the battery module, it is not possible to prevent the air moving in the space inside the indentation portion 340 from exploding to the outside.

FIG. 5 is an enlarged view of a battery module according to another embodiment of the present invention. Referring to FIG. 5, indentations 240 may be formed in the first bonding surface 230 of the battery module frame 200. . Likewise, the indentation 240 may be indented in a direction perpendicular to the first bonding surface 230 and may extend in a direction parallel to the sides 211 constituting the front surface of the battery module frame 200. .

Like the indentation portion 340 of FIG. 4 described above, the indentation portion 240 formed on the first bonding surface 230 also has compressed pores in which the first bonding surface 230 and the second bonding surface 330 are joined. It can play a role of preventing it from being sprayed out of the cotton. That is, the indentation portion 240 of the first bonding surface 230 has the same or similar configuration as the indentation portion 340 of the second bonding surface 330 described above, except for the position where the indentation portion 240 is formed. It can be applied, and repeated content is omitted.

Meanwhile, the indentation according to embodiments of the present invention may be formed on at least one of the first bonding surface and the second bonding surface. That is, it may be formed on one of the first bonding surface and the second bonding surface, and although not shown, may be formed on both the first bonding surface and the second bonding surface. However, if the indentation is formed on both the first bonding surface and the second bonding surface, it is preferable that the indentation formed on the first bonding surface and the indentation formed on the second bonding surface are located in regions that do not overlap each other for smooth welding.

6 and 7 are views showing variously modified indentations in an embodiment of the present invention.

4, 6, and 7, if the indentations 340, 341, and 342 can provide an air passage between the first bonding surface 230 and the second bonding surface 330, the shape is Since it is not limited, not only the V-shaped indentation 340, but also the rectangular indentation 341 or the semicircular indentation 342 may be possible.

Referring again to FIGS. 3 and 4, the end plate 300 further includes a protrusion 350 located at the center of the end plate 300 than the second bonding surface 330 and protruding toward the battery module frame 200. Can include. That is, based on FIG. 4 showing the upper side of the end plate 300, the protrusion 350 may be located below the second bonding surface 330, and although not shown, the protrusion based on the lower side of the end plate is removed. 2 It can be located on top of the junction surface. The same applies to the left and right sides of the end plate.

Meanwhile, the protrusion 350 may have a shape extending in a direction parallel to the sides of the end plate 300. That is, the first bonding surface 230 and the second bonding surface 330 may be connected along an area in which welding is formed.

Also, the protrusion 350 may be formed on at least one of the sides constituting the end plate 300. If necessary, it may be formed only on both sides facing each other, or may be formed on all sides.

When the battery module frame 200 is coupled with the end plate 300, since the protrusion 350 is inserted into the open front surface 201 of the battery module frame, the battery module frame 200 and the end plate 300 are It can be fastened without misalignment. In addition, since welding can be performed in a state in which the first bonding surface 230 and the second bonding surface 330 are in contact with each other by the protrusion 350, welding can be performed more easily. In addition, it is possible to prevent the occurrence of distortion in the welding part due to heat generated inside the battery module frame 200, and even if a slight distortion occurs, the distortion or protrusion in the welding part is the battery module frame ( 200) It is possible to prevent the internal battery cells or devices from being affected.

Meanwhile, each of the battery module frame 200 and the end plate 300 may include an aluminum alloy. More specifically, the battery module frame 200 may include an Al-Mg-based alloy such as Al 5052 or an Al-Mg-Si-based alloy such as Al 6063, and the end plate 300 is Al such as an ADC12 alloy. -It may include an alloy in which Mg and Mn are added to an Al-Si alloy such as a Si-Cu alloy or Silafont-36 alloy.

Meanwhile, referring to FIG. 3 again, the configuration for the front surface 201 of the battery module frame 200 described above may also be applied to the rear surface 202 of the battery module frame 200, as well as overlapping content. I will omit it.

The battery module described above can be applied to various devices. Such a device may be applied to a vehicle such as an electric bicycle, an electric vehicle, or a hybrid, but is not limited thereto, and may be applied to various devices capable of using a secondary battery.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of rights of

100: battery module
200: battery module frame
230: first bonding surface
300: end plate
330: second bonding surface
340: indentation
350: protrusion

Claims (10)

A cell stack including one or more battery cells;
A battery module frame housing the cell stack and having front and rear surfaces facing each other; And
And an end plate covering each of the front and rear surfaces of the battery module frame,
The battery module frame includes first bonding surfaces formed on sides constituting each of the front and rear surfaces,
The end plate includes a second bonding surface bonded to the first bonding surface,
A battery module having a recess formed in at least one of the first bonding surface and the second bonding surface. In claim 1,
The indentation portion, the battery module extending along a direction parallel to the sides constituting each of the front and rear surface of the battery module frame. In paragraph 2,
The indentation portion is a battery module indented in a direction perpendicular to the first bonding surface or the second bonding surface. In paragraph 2,
The indentation portion is formed to be spaced apart from sides of the first bonding surface or the sides of the second bonding surface. In claim 1,
The indentation portion is a V-shaped, square or semi-circular battery module. In claim 1,
Each of the battery module frame and the end plate includes an aluminum alloy. In claim 1,
The battery module wherein the first bonding surface and the second bonding surface are welded to each other. In claim 1,
The end plate is a battery module further comprising a protrusion positioned at the center of the end plate than the second bonding surface and protruding toward the battery module frame. In clause 8,
The protrusion is a battery module extending along a direction parallel to the sides of the end plate. A device comprising at least one battery module according to claim 1.

Images